I have a APS Small painkiller muzzlebrake forsale. I was going to put it on my 300RUM, but since then I sold the rifle. It's brandnew still with the package and directions he sent it in. If you need more info, go to his site. I bought it because he's one of the best gunsmiths PERIOD. Selling it for $130 shipped to your door in the lower 48.